Crucible-furnace.



No. 678,674. Patented July I6, I90L.

' 0. MICHAEL.

I GRUCIBLE FURNACE. (Application fllad June 14', 1901. (No Mode lhvrrnnSTATES nrnr rrrcn.

OTTO MICHAEL, OF FREIBURG, GERMANY.

CRUCIBLE FURNACE.

SPECIFICATION forming part of Letters Patent No. 678,674, dated July 16,1901. Application filed June 14, 1901. Serial No. 64,502. (No model.)

To all 2071 0121, it may concern.-

Be it known that I, OTTO MIcHAEL,foundryforeman, a subject of the GrandDuke of Baden, residing at Guntramstrasse 36, Freiburg, in the GrandDuchy of Baden and Empire of Germany, have invented certain new anduseful Improvements in Crucible-Furnaces, of which the following is afull, clear, and exact description.

In the whole industry of metal founding, and especially in theconstruction of cruciblefurnaces, a great many novelties have beenintroduced from time to time. They have been mostly of such anunpractical nature, however, that they have had to give wayto the oldprocesses-the crucible,cupola,and reverberatory furnacesnotwithstandingthat it has always been clear to those engaged in such industry that theold crucible-furnaces, which do not change the chemical composition ofthe smelting charge to any appreciable degree, work very unprofitably byreason of their great consumption of fuel.

It has been proposed, for instance, to place several crucibles in onefurnace or to set crucibles in fines a certain distance above the floorof the furnace for heating the mass where the heat of the waste gasesmay be utilized; but even in these methods a large and continuousconsumption of fuel is imperative, otherwise the heat will beinsufficient.

It is well if a really workable smelting plant is to be set up to startfrom the basis of utilizing the heat of waste gases before it escapesfarther into the fines leading to the stack without the heated cruciblesbeing placed in the oven for a second heating period. This is thepurpose and subject-matter-of the present invention, according to whichthe crucibles to be heated are placed within niches provided in themouths of the flues in the furnace on the same level as the usualgrating or floor, and the material contained in them becomes melted evenat the first period of warming, no matter whether it is not readilyfusible or otherwise, so that the contents of the crucible may be pouredout immediately after the first melting period, together with thosecrucibles that have passed through their second melting period.

Upon the accompanying sheet of drawings is shown the means for carryingout my in vention.

Figure 1 is a vertical section through the line A B of Fig. 2, and Fig.2 a horizontal section on line O D of Fig. 1.

The horizontal section of the crucible-chamber a of the oven is shownquadrilateral in Fig. 2; but it may be of any other shape. In the middleof each of the four walls is built a niche of curved form 1), four inall. These niches Z) are of convenient height, so that crucibles ormelting-pots 0, provided with covers d, can stand therein upon suitablebases e, the crucibles being introduced through the crucible-chamber ainto the niches l) at the mouths of fines f, which form a continuationof the niches b, and removed by the same way.

The floor of the crucible-chamber a is made ofagrating g, composed,preferably, of rectangular section-bars. Beneath and across the bars ofthe grating are two double T- girders h or a frame of similar section,which convey to the brick wall 2' of the furnace the weight of thefilled crucibles 13 standing on the grating g. Underneath the grating gis an ash-pit it, easily reachable and readily cleaned. Opening into theouter walls of the niches b somewhat, as shown in Fig. 1, are channelslat a suitable height above the crucibles 0, leading from the tines intothe stack. It is advantageous to let the individual branch channelsZlead into a common flue n built in the wall 2' of the furnace aroundthe crucible-chamber 0; before finally leading into the main flue, bywhich arrangement the draft from the individual channels Z can beequalized. For the purpose just mentioned it is advisable to make themain flue terminate at different points-for example, at two points inthe flue n, as shown by Fig. 2.

The surfaces of thefurnace that come in direct contact with the fire arepreferably covered with dolomite, ganister, or like suitable material.

The above-mentioned operation takes place in the crucible-furnaceaccording to the present invention as follows: Supposingthefourcrucibles p standingin the middle of the crucible-chamber a to be takenout (together with the molten material contained therein) and the lid q(made of stone, &c.) removed and the interior of the shaft thus exposed,the crucibles c,which were heated during the last smelting, so as tomelt the greater part of the contents, are then taken out one by one,while other crucibles 0, containing fresh uninelted material, are put inplace thereof into the niches b. The crucibles c, which have just beenremoved from the niches b after their first heating, are now assembledin the places previously occupied by the crucibles p, as shown in thedrawings, in the center of the crucible-chamber a, Where they remain forthe second heating. The space in the crucible-chamber a between theseparate pots or crucibles p is filled up with coke, which done thesecond heating begins.

What I claim, and desire to secure by Letters Patent, is

1. A crucible-furnace comprising a crucible-chamber, niches in the wallsof the chamber for the reception of crucibles to be preheated, channelsleading from the outer walls of the niches, and means for heating thefurnace. V

2. A crucible-furnace comprising a crucible-chamber, niches in the wallsof the chamber for the reception of crucibles to be pre-- heated,channels leading from the outer walls of the niches, a main fiuesurrounding the chamber and common to all the channels, and means forheating the furnace.

3. A crucible-furnace comprising a crucible-cha1nber, means for heatingthe furnace having a grate, niches in the walls of the chamber for thereception of crucibles to be preheated, having floors on the same levelas the grate and channels leading from the outer walls of the niches.

In witness whereof I subscribe my signature in presence of twoWitnesses.

OTTO MICHAEL.

Witnesses:

GEORGE SCHMITT, CHRISTIAN WEILBRENNER.

